I think `Union[SomeType, None]` is more explicit about what it means.

It's just about the words and names. But those words can affect how you and your teammates think about the code.

As an example, let's take this function:

```python
from typing import Optional

You can learn more about [FastAPI versions and how to pin and upgrade them](https://fastapi.tiangolo.com/deployment/versions/) for your project in the docs.

## Reporting a Vulnerability

 */
package org.apache.maven.artifact.resolver.filter;

import java.util.List;

import org.apache.maven.artifact.Artifact;

/**
 * Filter to exclude from a list of artifact patterns.
 *
 * TODO I think this is equiv. to exclusion set filter in maven-core
 */
public class ExcludesArtifactFilter extends IncludesArtifactFilter {
    public ExcludesArtifactFilter(List<String> patterns) {
        super(patterns);
    }

/// tip

This is the ultimate **vibe-driven development** experience. You don't need to think about what your API does, just let the LLM handle it. 🧘

///

## Try It { #try-it }

Go ahead, try it:

{* ../../docs_src/vibe/tutorial001_py310.py *}

    isInterruptibleRegistered.await();
    RuntimeException expected = assertThrows(RuntimeException.class, task::interruptTask);
    assertThat(expected)
        .hasMessageThat()
        .isEqualTo("I bet you didn't think Thread.interrupt could throw");
    /*
     * We need to wait for the runner to exit. It used to be that the runner would get stuck in the
     * busy loop when interrupt threw.
     *

    isInterruptibleRegistered.await();
    RuntimeException expected = assertThrows(RuntimeException.class, task::interruptTask);
    assertThat(expected)
        .hasMessageThat()
        .isEqualTo("I bet you didn't think Thread.interrupt could throw");
    /*
     * We need to wait for the runner to exit. It used to be that the runner would get stuck in the
     * busy loop when interrupt threw.
     *

            println("CACHE_MISS in task $taskPath")
            cacheMiss.set(true)
        }
    }
}


/**
 *  We monitor some tasks in non-seed builds. If a task executed in a non-seed build, we think it as "CACHE_MISS".
 */
fun isCacheMissMonitoredTask(task: Task) = task.isCompileCacheMissMonitoredTask() || task.project.isAsciidoctorCacheMissTask()

Pull requests
-------------

Unless the change is a trivial fix such as for a typo, it's generally best to
start by opening a new issue describing the bug or feature you're intending to
fix. Even if you think it's relatively minor, it's helpful to know what people
are working on. And as mentioned above, API changes should be discussed
thoroughly before moving to code.

Using these `dependencies` in the *path operation decorator* you can make sure they are executed while avoiding editor/tooling errors.

It might also help avoid confusion for new developers that see an unused parameter in your code and could think it's unnecessary.

///

/// info

In this example we use invented custom headers `X-Key` and `X-Token`.

          </excludePackageNames>
          <!-- Ignore some tags that are found in Java 11 sources but not recognized... under -source 8, I think it was? I can no longer reproduce the failure. -->
          <tags>
            <tag>
              <name>apiNote</name>
              <placement>X</placement>
            </tag>
            <tag>